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Abstract

The value of restoring and maintaining sinus rhythm in pts with atrial fibrillation (AF) and congestive heart failure (CHF) is controversial. The AF-CHF trial randomized 1376 pts with atrial fibrillation (AF), ejection fraction less than or equal to 35%, and symptoms of CHF to a rhythm-control vs a rate-control strategy. Patients assigned to rhythm-control received antiarrhythmic drugs (>80% amiodarone), and cardioversion if needed. No attempts to restore or maintain sinus rhythm were performed in rate-control pts. The primary analysis previously reported was based on an intention-to-treat approach, and showed no significant difference in cardiovascular or total mortality. However, sinus rhythm cannot be maintained in all rhythm-control pts, some rate-control pts were free of AF, and 15.1% of pts crossed-over from one treatment strategy to the other. We, therefore, performed a time-dependent efficacy analysis based on the presence or absence of AF during follow-up (fu). Pts were followed every 4 mos for 4 yrs, and every 6 mos thereafter. Each fu period was classified for the presence or absence of AF based on clinical and ECG data. Presence or absence of AF was modeled as a time-dependent covariate irrespective of treatment strategy using an adjusted Cox multivariate regression model.

RESULTS: The average age of the population was 67 yrs, 82% were male, 48% had coronary disease, 31% had NYHA 3– 4 CHF, and average EF was 27+/− 6%. After a mean fu of 37 mos, 445 (32%) pts died, 357 of cardiovascular (CV) death. The median proportion of time spent in AF was 39% for the entire cohort. This table⇓ depicts the covariates and hazard ratios (HR) retained in the final model.

CONCLUSION: This efficacy analysis of AF-CHF indicates that AF does not predict cardiovascular or all-cause mortality once the severity of clinical symptoms and mitral regurgitation are known. These results further indicate that rate control is an appropriate initial treatment option in patients with heart failure.